 (defn draw
   "Draw on canvas"
   [canvas _ _ state]
-  (let [vehicles (or state (repeatedly 120 make-vehicle))]
+  (let [vehicles (or state (repeatedly vehicles-no make-vehicle))]
     (-> canvas
         (set-background :linen)
         (set-color :black 100)

(def ^:const ^int w 640)
(def ^:const ^int h 360)
(def ^:const ^int resolution 15)

(def ^:const cols (int (/ w resolution)))
(def ^:const rows (int (/ h resolution)))

                                                    (translate x y)
                                                    (rotate (v/heading v))
                                                    (line 0 0 (/ resolution 1.5) 0)
                                                    (ellipse 0 0 3 3)
                                                    (pop-matrix)))) vv))) field))
  canvas)

(deftype Vehicle [position
                  velocity
